BOSTON (CBS/AP) — The candidates in the closely-watched Massachusetts U.S. Senate race looked to seize the momentum coming off their first head-to-head debate of the campaign.

Republican U.S. Sen. Scott Brown went back on the offensive Friday, again criticizing Democratic challenger Elizabeth Warren’s role in a complex U.S. Supreme Court case involving a mining company that set up a trust fund for victims of asbestos poisoning.

Brown claimed the Harvard Law School professor was paid nearly $250,000 by Travelers Insurance to help defend the company against asbestos poisoning settlements.

The Republican has raised the issue before, including during Thursday night’s debate. Warren has said her role was that of a consultant in the case involving a mining company and that she defended the use of trust funds to ensure that all asbestos victims would be paid.

“You see, Professor Warren is not just a Harvard professor,” Brown said at a news conference at his campaign headquarters. “She is also a hired gun, and in the case of Travelers Insurance — she was hired to get them off the hook for settlements sought by victims of asbestos poisoning.”

Brown said the case undermines the Democratic campaign’s claim that Warren, who helped create a federal consumer protection agency after the Wall Street meltdown, always stands up for workers over big corporations.

The Warren campaign struck back quickly on Friday, making available David McMorris, a lawyer who represented asbestos victims in the case. He strongly defended Warren’s role and accused Brown of launching an unfair attack.

“It’s a completely dishonest, misleading, and I would say intentionally misleading ploy by Senator Brown, and it’s really shameful,” said McMorris, who was joined by a representative of the asbestos workers union.

Brown’s campaign retorted that McMorris was a major Democratic donor who has contributed to Sen. John Kerry and President Barack Obama, among others.

Warren, a bankruptcy expert, argued in the 2009 Supreme Court case that Travelers should be protected from future lawsuits from victims because such suits would prevent similar trusts from being created, making impossible for all victims to be paid. Such trusts shorten the time for victims to receive payments and allow future victims to be compensated, not just the first to sue, Warren maintains.

Brown argued that in this case, asbestos victims were forced to settle for lifetime payments totaling a fraction of what Warren received as a “high-powered” attorney in the case.

Warren did not respond directly to the issue when Brown raised it during the debate, but later told reporters that an important legal principal had been at stake in the case and that she would do the same again. The Democrat has disclosed the payments from Travelers and a legal firm representing the company in previous federal financial disclosure reports.

Warren later appeared at a rally in Boston, where she received the endorsement of Democratic Boston Mayor Thomas Menino.

Menino, a Democrat said he held off making a decision until now because he wanted to take time to get to know Warren and her positions better.

Menino said after getting to know her, Warren has his vote and his help as the mayor of the state’s largest city.

“Elizabeth Warren is good people,” said Menino. He told a crowd of supporters her work, “would make Teddy proud,” a reference to the late Senator Ted Kennedy.

Menino said he likes Brown, but said Brown was “wishy washy” on jobs, housing protection and other issues.

While Warren expressed her support for Obama at several junctures during the debate, her campaign made a point on Friday to note that Brown never once mentioned Mitt Romney, the former Massachusetts governor and Republican presidential nominee. Polling has suggested Romney trails Obama in his home state by a wide margin.

Brown answered “of course” when asked if he still supported Romney, adding that while he doesn’t agree with Romney on everything believes he’s the best candidate to address the nation’s economic issues.

“She’s not running against Mitt Romney, she’s running against me,” Brown said of Warren.